News

EURAMET is happy to announce that the revised version of its Calibration Guide No. 18 'Guidelines on the Calibration of Non-Automatic Weighing Instruments' has been published.

The purpose of the guide, from the field 'Mass and Related Quantities', is to enhance the equivalence and mutual recognition of calibration results obtained by laboratories performing calibrations of non-automatic weighing instruments. It contains advice on general aspects of calibration, measurement methods and results, including uncertainty of measurement, the calibration certificate and the use of mass or conventional mass values.

EURAMET's Calibration Guide No. 18 was first published more than 10 years ago and has been regularly updated since then. The guide has become one of the most requested documents provided by EURAMET. "It was adopted by other Regional Metrology Organisations and is widely used by accreditation bodies as a mandatory document. This latest update is the first review involving direct collaboration with balance manufacturers," explains Nieves Medina Martin (CEM, Spain) who coordinated the EURAMET project 'Review of EURAMET cg 18: Guidelines on the Calibration of Non-Automatic Weighing Instruments'.

Important improvements of the 4th version include: clarification in the use of substitution loads, calculation for the eccentricity test, a more accurate formula for uncertainty related to the correction for air buoyancy, better approximation for air density variation, improved approximation methods, determination of minimum weight and better understanding of the effect of balance adjustment. There are no changes to the underlying calibration procedures.

The 4th version of the EURAMET Calibration Guide No. 18 was developed thanks to the cooperation of Stuart Davidson (NPL, United Kingdom), Klaus Fritsch (Mettler Toledo, Switzerland), Matej Grum (MIRS, Slovenia), Andrea Malengo (INRIM, Italy), Nieves Medina (CEM, Spain), George Popa (INM, Romania) and Norbert Schnell (Sartorius, Germany).